Patent GB-257502-A (GB)
Title: Improvements in and relating to pictures and their production by colour-photography
IPC: G03C7/10
Filed: 1925-05-26
Abstract: 257,502. Cook, E. S. May 26, 1925. Colour photography, screens and screen plates for.-A machine for ruling multicolour line screens comprises a marking roller for each colour, the several rollers operating successively upon the screen and having their marking surfaces displaced from one another laterally of the path of movement of the screen by the spacing of the lines. so that the colours are ruled in juxtaposition. The marking rollers comprise discs of felt, or felt-coated metal, secured upon a common spindle and spaced by discs of smaller diameter. The periphery of each marking disc may be continuous or broken, so that continuous or broken lines may be ruled. Fig. 2 shows a portion of the machina, including the elements for printing the lines of one colour only, and adapted to rule a screen upon a kinematograph film. The film is drawn along the recessed underside of a guideplate 1 by rollers 15, 16 which are driven by a handle 27 and carry flanges which press on the margins of opposite sides of the film. These rollers may be forced together against spring pressure by adjusting screws 17a to vary their grip upon the film. The coloured lines are ruled by a marking roller 5, constructed as described above, the periphery of which receives marking material from a roller 6 rotating in partial immersion in a trough 7, which is provided with the material through a constant-level automatic supply valve. and is surrounded by a jacket 32 through which fluid may be passed to maintain the temperature of the material constant. The spindle of the roller 5 is mounted in bearings in blocks 9 displaceable vertically on the frame of the machine against the action of springs by adjusting screws 12 to vary the pressure of the roller upon the film ; and the spindle of the roller 6 is mounted in bearings in blocks 8 similarly adjustable by screws 11 in a horizontal direction in the blocks 9 to vary the pressure of the inking rollers 6 on the marking rollers 5. These rollers are driven from the pressure rollers 16 by chain and sprocket gearing on both sides of the machine, the chain being depressed at various points, to ensure its proper engagement with the rollers, by vertically adjustable jockey sprocket wheels 29. A removable trough 33, the walls of which conduct heat poorly, is mounted adjacent to the film surface and contains cooling or heating medium when it is desirable to cool or heat the film between the successive colour printings. A wiper comb. or brush may be mounted near the marking roller 5 for cleaning its periphery. The complete machine comprises a series of sections identical with that described above, one for each colour to be printed, the film passing directlv from the marking roller 5 of one section to the driving rollers 15, 16 of the next section, and the marking surfaces of the rollers 5 of successive sections being laterally staggered to print the colours in juxtaposition. Colour screen material incorporated with the sensitive emulsion, as described in Specification 257,501, may be applied by this machine. Specification 8761/10 is referred to.